A novel concept to generate single photons: incoherent conversion from the visible into the infrared spectrum

Abstract

Further improvement of infrared single photon sources is a major challenge for future implementations of quantum information and quantum communication applications. In this paper, we give further insight into a recently presented, conceptually novel method for the generation of single photons. 1 The method is of particular interest for spectral domains where stable room temperature single photon sources are not available. For example, this is the presently the case for the near-infrared. This wavelength regime is important for data transfer over long distances where optical losses in fibers are minimal. The presented method is based on the following idea. The fundamental key requirement for single photon generation is the generation of a single excitation in an optically active system. It is not the presence of a single quantum system. The presented method is applied to realize a stable, non-blinking, room temperature infrared single photon source by converting visible single photons from a defect center in diamond to the near infrared. For the presented implementation, the theoretical conversion efficiency was estimated to be 26 %. In a first prove of principle experiment, a conversion efficiency of 0.1 % was achieved.